Why dark skies are actually good for your health

And that’s not all that darkness can do for you. A 2020 study showed that realigning the circadian clock  with a compound that activates melatonin receptors in the brain can lower inflammatory markers, reduce anxiety, and alleviate depression.

The science of awe

Evidence is also mounting that the same alchemy that we feel in a dark sky sanctuary—a sense of wonder as we contemplate the vastness of the cosmos—is associated with better mental health and happiness.

It has long been clear that spending time in nature is good for your mental health—and a 2024 study published in the Journal of Environmental Psychology suggests that this benefits hold true at night as well as during the day.

(Nature really is good medicine. Science can explain why.)

“Experiencing natural darkness triggers a sense of awe and wonder in people which may be protective of human health,” says Ruskin Hartley, the executive director of Dark Sky International, a nonprofit group based in Tucson, Arizona, that has certified over 220 International Dark Sky places since 2001 and closely monitors the academic research on light pollution and darkness.

U.C. Berkeley professor Dacher Keltner captured this feeling in his 2023 book Awe: The New Science of Everyday Wonder and How It Can Transform Your Life. He argued that “awe is about our relation to the vast mysteries of life.” It is an emotion that has real biological implications: It can help lower the body’s inflammatory cytokine response—its response to attacking pathogens—as well as calm our nervous systems and trigger the release of oxytocin, a hormone that promotes positive feelings and is sometimes called the “love drug.”

The psychological benefits to spending time in the dark can be profound. Both mindfulness and creativity can be encouraged by darker spaces, as people who go to churches, synagogues, and mosques have discovered for millennia. There is a deeper reason why the lights go down before the curtains rise in theater productions and cinemas: darkness creates a liminal space where imaginations can flow more freely. The dimming light at dusk is nature’s own curtain fall.

How much darkness do you need?

My own fascination with the dark began in October of 2022, when I found myself floating in a Zodiac raft in the Arctic Sea. Our expedition guide had motored our rubber raft away from the artificial lights of our larger vessel, turned the outboard engine off, and instructed us to be silent. My shipmates and I looked up into the immensity of the celestial bowl as constellations spun in the black sky above. The darkness was so dense I couldn’t tell up from down, or where the night sky ended, and the inky sea began. I felt disoriented and elated.

I felt a surge of positive feelings flowing through me as I looked up at the stars on that dark Arctic night. The experience changed my relationship to darkness. As someone who’d always relished the idea of going to bed early to get a good night’s sleep, I decided to turn off artificial lights and electronic devices earlier in the evening. I also began wondering what “dose” of dark each night was ideal for my health.

(7 science-backed tips for better sleep.)